Highly efficient cooling systems

ABSTRACT

Improved structures of cooling systems that may be used in air conditioning or refrigeration are described. To achieve a high efficiency in converting cooling effect from one or more cooling units, antifreeze liquid used to absorb the cooling effect is forced to pass through a box or container made out of graphite or thermally conductive metal or alloy holding a sponge-like structure or foam, also made out of graphite or thermally conductive metal or alloy, where the foam including open cells provides maximum surface contact with the liquid. Further the liquid is sprayed or vaporized onto the foam and passes through the foam by gravity or pressure. The cooled liquid is exited from the container for use in air conditioning or refrigeration.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is generally related to the area of air conditioningsystems or refrigeration. More particularly, the present invention isrelated to cooling systems with a unique structure to deliver coolingeffect in highly efficient way, where the cooling systems use lessenergy than the prior art systems do and can be used in air conditioningsystems or refrigeration.

2. The Background of Related Art

Prior to the introduction of Freon in 1928, the air conditioningindustry relied on dangerous, toxic, and/or flammable liquids and gasesto act as refrigerants. In 1928, chlorofluorocarbon compounds such asFreon were introduced and deemed to be more efficient and effectiverefrigerants for air conditioning systems. However, such compounds ifreleased into the atmosphere were discovered to cause severeenvironmental effects, such as the depletion of the ozone layer, andcontribute to the global warming.

Currently standard refrigerants (e.g., R-22) are scheduled to be phasedout in new equipment by 2010, and completely discontinued by 2020.However, the newer refrigerants prove to cause similar environmentimpact of its predecessors. Moreover, the traditional split airconditioning system, comprised of a compressor and air handler, uses alarge amount of electricity to perform the cycle of evaporating and thencondensing the chlorofluorocarbon refrigerants to cool down therefrigerants and run them through the air handler. The process causesfurther environment effects such as depletion of fossil fuels, as wellas being expensive to the end user, especially with the recent rises inthe cost of such fuels.

One other aspect of the traditional air conditioning compressor is itshigh noise level, which requires the unit to be placed outside and somedistance away from the air handler, which in turn causes a loss ofefficiency due to temperature lost from its travel from the compressorto the air handler.

Water was used as early as in the 2nd century during the Chinese SongDynasty as a coolant into rudimentary fans as air conditioning. Eventoday, water is being used in large industrial and commercial waterchilled air conditioning systems. However using traditional evaporativeand condensing mechanism uses a large amount of energy. Thus there is aneed for energy efficient, environmental friendly, and quiet airconditioning systems.

SUMMARY OF THE INVENTION

This section is for the purpose of summarizing some aspects of thepresent invention and to briefly introduce some preferred embodiments.Simplifications or omissions in this section as well as in the abstractor the title of this description may be made to avoid obscuring thepurpose of this section, the abstract and the title. Suchsimplifications or omissions are not intended to limit the scope of thepresent invention.

In general, the present invention pertains to highly efficient coolingsystems. According to one aspect of the present invention, an airconditioning system runs an energy-efficient water chilled mechanismthat can be used on smaller scales as well as large properties. The airconditioning system achieves peak efficiency by using unique physicalproperties of solid carbon graphite, carbon graphite and/or metallicfoam, and misters to achieve maximum thermal conductivity fromabsorption to water.

According to another aspect of the present invention, two cooling unitsare used to sandwich a container made out of a type of metal, carbongraphite, or combination thereof, with high conductivity. The containeris structured to include a metal foam in contact with the containerbeing sandwiched by the two cooling units. As a result, liquid in thecontainer is substantially cooled to provide a cooled source for airconditioning or refrigeration.

There are numerous functions, benefits and advantages in the presentinvention, one of them is that the present invention provides newstructures for a cooling system that may be used in air conditioning orrefrigeration. The present invention may be implemented in numerousfoams. According to one embodiment of the present invention, the presentinvention is a cooling system comprising: a container including an inletand outlet, a foam included and expanded in the container so that thefoam is in close contact with the container, and two cooling unitssandwiching the container to transfer cooling effects to the container,where a type of liquid is supplied from the inlet to pass the foam to becooled, and the cooled liquid exits from the outlet.

According to another embodiment of the present invention, the presentinvention is a cooling system comprising: a container including an inletand outlet, a foam included and expanded in the container so that thefoam is in close contact with the container, where the foam is made outof a material with high thermal conductivity, and allows for optimalsurface area of cooling, the foam includes open cells, two cooling unitssandwiching the container to transfer cooling effects to the containerthen the foam inside the container, where a type of liquid is suppliedfrom the inlet to be sprayed over the foam that passed through the foamby gravity and/or pressure, and the outlet exits the liquid that hasbeen cooled when going through the container.

Other objects, features, and advantages of the present invention willbecome apparent upon examining the following detailed description of anembodiment thereof, taken in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood with regard to the followingdescription, appended claims, and accompanying drawings where:

FIG. 1 shows a cooling unit that may be used in one embodiment of thepresent invention;

FIG. 2A shows a side view of a structure with a container beingsandwiched by two cooling units;

FIG. 2B shows a detailed structure of the container used in FIG. 2; and

FIG. 3 shows an embodiment in which a compressor is used.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention pertains to new structures of cooling systems thatmay be used in air conditioning or refrigeration. To achieve a highefficiency in converting cooling effect from one or more cooling units,antifreeze liquid used to absorb the cooling effect is forced to pass abox or container holding an open-cell sponge-like structure or foam,where the foam including holes provides maximum surface contact with theliquid. Further the liquid is sprayed or vaporized onto the foam and theliquid passed through the foam by gravity. The cooled liquid is exitedand pumped from the container for use in air conditioning orrefrigeration.

The detailed description of the present invention is presented largelyin terms of procedures, steps, logic blocks, processing, or othersymbolic representations that directly or indirectly resemble theoperations of devices or systems that produce coldness or coolingeffect. These descriptions and representations are typically used bythose skilled in the art to most effectively convey the substance oftheir work to others skilled in the art.

Reference herein to “one embodiment” or “an embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment can be included in at least one embodiment of theinvention. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment, nor are separate or alternative embodiments mutuallyexclusive of other embodiments. Further, the order of blocks in processflowcharts or diagrams or the use of sequence numbers representing oneor more embodiments of the invention do not inherently indicate anyparticular order nor imply any limitations in the invention.

One of the important features, advantages and objectives in the presentinvention is the use of two cooling units to cool down a container beingsandwiched by the two cooling units. The container containing at least asponge-like structure or foam that is expanded within the container tobe closely in contact therewith. The container itself is made out of atype of material with high thermal conductivity. The foam is also madeout of a type of material with high thermal conductivity. Each of thecooling units operates on absorptive refrigeration that uses a source ofheat to provide the energy needed to drive the cooling process.According to one embodiment, the source of heat is provided by solarenergy. With solar panels being exposed to the sun, electricity isgenerated to power the source of heat to heat up a type of liquid beingused in the cooling units. In another embodiment, the source of heat isprovided by conventional electric resistance heater. Examples of theliquid used as refrigerant include, but not be limited to, ammonia,hydrogen, and water.

Referring now to the drawings, in which like numerals refer to likeparts throughout the several views. FIG. 1 shows a cooling unit 100 thatmay be used in one embodiment of the present invention. As shown in FIG.1, the cooling unit 100 is shown in two views, referred to herein as aninside view 102 and an outside view 104. The cooling unit 100 comprisesa heating area 106, a cooling area 108, an absorber tank 110, andabsorber 112. The heating area 106 includes a boiler (not separatelyshown) powered by energy provided externally. In one embodiment, theenergy is from electricity generated from solar. In another embodiment,the energy is from battery or conventional electric power.

The boiler heats up a type of liquid (e.g. ammonia) coming from theabsorber tank 110. To facilitate the description of the invention,ammonia will be used herein. As a result of the ammonia liquid beingheated, the ammonia liquid vaporizes. The ammonia vapor is led to passinto the cooling area 108, where there is a set of coils or bendingpipes 114 that make up a rectifier and an evaporator. The rectifier isjust a slightly cooler section of the pipes 114 that cause the vapor tocondense and drop back downwards. An optional separator (not shown) atthe top of the cooling unit 100 prevents any liquid that might haveescaped the rectifier to condense and fall back. After this point, thevapor is delivered to the condenser. A condenser is where the cooled airpassing through the ammonia vapor being cooled down. The cooling effectof the condenser with an array of metal fins forces the ammonia vapor tocondense to a liquid state.

The liquid ammonia enters the evaporator (or a freezer) and tricklesdown the pipes, wetting the wall thereof. Hydrogen, supplied through aninner pipe of the evaporator, passes over the wetted wall, causing theliquid ammonia to evaporate into the hydrogen atmosphere at an initialtemperature of around −20° F. The evaporation of the ammonia extractsheat from the surrounding (e.g., a freezer). In operation, at thebeginning stages, the pressure of the hydrogen is around 350 psi (poundsper square inch), while the pressure of the liquid ammonia is near 14psi. As the ammonia evaporates and continues to trickle down the tube,its pressure and therefore its evaporation temperature rise.

The liquid ammonia entering the high temperature evaporator (coolingportion) is around 44 psi while the pressure of the hydrogen has droppedto 325 psi. Under these conditions, the evaporation temperature of theliquid ammonia is +15° F. Heat is removed from the surrounding throughthe fins attached to the high temperature evaporator. The ammonia vaporcreated by the evaporation of the liquid ammonia mixes with the alreadypresent hydrogen vapor, making it heavier. Since the ammonia andhydrogen vapor mixture is heavier than the purer hydrogen, it drops downthrough the evaporators, through the return tube to the absorber tank.

When the ammonia and hydrogen vapor mixture enters the absorber tank 110through the returning tube or absorber 112, much of the ammonia vapor isabsorbed into the surface of the rich ammonia solution while goingthrough the absorber 112. The rich ammonia solution occupies the lowerhalf of the tank 110 while lighter ammonia and hydrogen mixture (nowwith less ammonia) begins to rise up in the absorber 112 (coils). Theweak ammonia solution trickling down the absorber coils 112 from the top(generated by the boiler) is “hungry” for the ammonia vapor rising upthe absorber coils with the hydrogen. This weak ammonia solutioneventually absorbs all the ammonia from the ammonia and hydrogen mixtureas it rises, allowing pure hydrogen to rise up the inner pipe of theevaporator section and once again do its job of passing over the wettedwalls of the evaporator. The absorption process in the absorber sectiongenerates heat, which is dissipated.

Referring now to FIG. 2A, it shows a side view of a structure 200 with acontainer 202 being sandwiched by two cooling units 204 and 206according to one embodiment of the present invention. The cooling unit100 of FIG. 1 may be used. The container 202 is preferably made ofgraphite, but could also be made of aluminum, copper, or any otherthermo-conductive metal or alloy including non-metallic ceramic. Thecontainer 202, as further shown in FIG. 2B, includes a foam 214 made outof graphite or a metal material with high thermal conductivity. The foam214 is expanded within the container 202 to be closely in contacttherewith so that coldness or cooling effect from the two cooling units204 and 206 can be effectively transferred therein. In one embodiment,on top of the container 202 there is an optional gasket (formaintenance) and a liquid (or gas) inlet 208. A mister 210 is employedto be connected to the inlet 208.

In operation, a type of liquid (e.g., antifreeze liquid) is supplied tothe inlet 208 that causes the mister 210 to spray or vaporize the liquidinto the foam 214. By gravity, the mist 220 falls inside cells of thefoam 214. In one embodiment, the foam 214 similar to a sponge-likestructure, is made out of graphite with open cells measured, forexample, between 10-100 PPI (pores per inch) in size. As the mist 220falls downwards, the liquid passed through the foam 214. From anotherperspective, the liquid is having the maximum surface contact with thefoam 214. As a result, the cooling effect or coldness from the twocooling units 204 and 206 are transferred to the liquid in maximumefficiency. The cooled liquid exits to an outlet 220 at its coldesttemperature.

It should be noted in FIG. 2A that the coils or tubes (not shown) in thetwo cooling units 204 and 206 that produce the cooling effect areentrenched in insulator 218 but in close contact with the container 202to transfer the cooling effect. According to one embodiment,thermo-conductive paste is used to ensure that maximum transfer of thecooling effect to the container 202 is achieved.

The cooled liquid from the outlet 220 can optionally go to a tank thento a pump, or directly to a pump connected (using any tubing) to anevaporator cooling coil located inside an air handler that receive thecold liquid, pushed by the pump. In one embodiment, the liquid goesthrough copper tubing surrounded by aluminum fins, the air going throughthe fins becomes cold and pushed by a blower to ducts. The liquid duringthis process heats up and comes back to the container 202 to get cooledagain in a closed loop.

As indicated above, the invention as described herein provides an energyefficient liquid chilled system that can be used on smaller scales aswell as large properties, and forgoes the high energy consumption of atraditional compressor for the lower energy usage of an absorptioncooling system. A system built per the present invention achieves peakefficiency by using the unique physical properties of solid carbongraphite, carbon graphite and/or metallic foam, and misters to achievethe maximum thermal conductivity from the absorption system to theliquid.

According to one embodiment, the present invention is implemented as acentral air conditioning system, where a blower (e.g., air handler)receives a cold liquid or gas (less than 45 F), that is pumped from acarbon graphite reservoir that is sandwiched between two or moreabsorption cooling units, and where the solid carbon graphite reservoiris filled with a graphite and/or metal (copper, aluminum, silver, alloy,etc.) foam. The thermal conductivity properties of the graphite withinthe reservoir and the foam transfer the cold temperature from theabsorption units to the liquid or gas. This liquid or gas is used tocool the air that blows through the air handler coil. The liquid or gasis then pumped back to the top of the graphite reservoir, where there isa mister (if it is in liquid form) that atomizes the molecules of theliquid, and acts as an initial cooling of the liquid, which is thensprayed back into the graphite reservoir to repeat the cooling cycle.

The thermodynamic exchange is maximized in the present invention due tothe porosity of the foam which increases the surface cooling areaexponentially. Furthermore, the unique thermal properties of the carbongraphite within the reservoir and/or the foam stores the coldtemperature, therefore allowing a constant thermal conduction, rapidrecovery, at a constant temperature, using minimal power.

Depending on implementation, the foam (e.g., the foam 214) by itself canbe made of one metal or graphite or alloy, or a combination of differentfoams, without any limitations in size or orders. Certain metals such assilver may be included for the additional effect of cleaning the waterwithin the unit and preventing the growth of mold and bacteria.

The liquid or gas circulating can be water alone, water with glycol(antifreeze), in any proportion, or any gas like CO2, Helium, orhydrogen. If a gas is used, the unit will be sealed under pressure tomaintain gas thermo effectiveness.

In one embodiment, an optional mechanism of (electronically) controlledtanks is provided before the mist and/or before the pump (cold outlet)to run the pump at an optimal rate, as well as run the absorptioncooling units to maintain optimal energy efficiency. The unit may alsoinclude an optional compressor, or use an existing compressor, toinitially cool the unit if the unit has not been recently used. Theenergy usage is sufficiently efficient to run on 12 volts, and permitthe entire air conditioning system to run on solar panels or otheralternative energy source.

Referring now to FIG. 3, it shows a hybrid configuration 300 in which acompressor 302 is used. Due to the absorptions cycles, it may takesometime for the two absorptions units to work at efficient temperaturesor setup load, then an optional compressor may be provided to performthe task to cool down the box the container 202 of FIG. 2A or 2B). As aresult, the waiting time after installation or if the unit has beenturned off can be minimized to have the system fully ready to cool downthe air. In an even that an external temperature rises up to a pointthat will make the absorptions cycles difficult then the compressor willhelp maintaining the proper temperature, despite the sporadic usage ofthe compressor will still provide an high level of energy efficiencywhile providing an acute temperature control level.

Like any other HVAC system, a thermostat connected to the air handler isused to control the operations of an air conditioning unit implementedin accordance with the present invention. Typically, the surrounding ofthe two cooling units is vented, the coils or pipes are properlyinsulated using any material (e.g., insulation foam, closed cells glassfoam). An venting area located at the bottom of the cooling units aswell as a small fan located at the top of the units to extract thelatent heat to an external air vent located outside a building (outsideair).

The present invention has been described in sufficient details with acertain degree of particularity. It is understood to those skilled inthe art that the present disclosure of embodiments has been made by wayof examples only and that numerous changes in the arrangement andcombination of parts may be resorted without departing from the spiritand scope of the invention as claimed. Accordingly, the scope of thepresent invention is defined by the appended claims rather than theforegoing description of embodiments.

1. A cooling system comprising: a container including an inlet andoutlet; a foam included and expanded in the container so that the foamis in close contact with the container; and two cooling unitssandwiching the container to transfer cooling effects to the container,wherein a type of liquid is supplied from the inlet to pass through thefoam to be cooled, and the cooled liquid exits from the outlet.
 2. Thecooling system as recited in claim 1, wherein the container is made outof a material with high thermal conductivity.
 3. The cooling system asrecited in claim 2, wherein the material is graphite, aluminum, copper,or other thermally conductive metal or alloy.
 4. The cooling system asrecited in claim 2, wherein the foam is made out of a material with highthermal conductivity and includes open cells, where the liquid passesthrough.
 5. The cooling system as recited in claim 4, wherein thematerial is graphite or thermally conductive metal or alloy.
 6. Thecooling system as recited in claim 4, wherein the cells are measured inrange of 10-100 PPI (pores per inch).
 7. The cooling system as recitedin claim 4, wherein the cells provide a maximum surface contact betweenthe liquid and the foam.
 8. The cooling system as recited in claim 7,wherein the liquid includes water, antifreeze, or a combination thereof.9. The cooling system as recited in claim 1, wherein the liquid afterbeing cooled in the container is used to cool down air in an airhandling unit.
 10. The cooling system as recited in claim 1, wherein theliquid after being cooled in the container is used to cool down anenclosure in a refrigerator.
 11. A cooling system comprising: acontainer including an inlet and outlet; a foam included and expanded inthe container so that the foam is in close contact with the container,where the foam is made out of a material with high thermal conductivity,the foam includes open cells; and two cooling units sandwiching thecontainer to transfer cooling effects to the container then the foaminside the container, wherein a type of liquid is supplied from theinlet to be sprayed over and passes through the foam by gravity orpressure; and wherein the outlet exits the liquid that has been cooledwhen going through the container.
 12. The cooling system as recited inclaim 11, wherein the container is made out of a material with highthermal conductivity.
 13. The cooling system as recited in claim 12,wherein the material is graphite, aluminum, copper or other thermallyconductive metal or alloy.
 14. The cooling system as recited in claim12, wherein the foam is made out of a material with high thermalconductivity and includes open cells where the liquid passes through.15. The cooling system as recited in claim 14, wherein the material isgraphite or thermally conductive metal or alloy.
 16. The cooling systemas recited in claim 14, wherein the cells are measured in range of10-100 PPI (pores per inch).
 17. The cooling system as recited in claim14, wherein the cells provide a maximum surface contact between theliquid and the foam.
 18. The cooling system as recited in claim 17,wherein the liquid includes water, antifreeze, or combination thereof.19. The cooling system as recited in claim 11, wherein the liquid afterbeing cooled in the container is used to cool down air in an airhandling unit.
 20. The cooling system as recited in claim 11, whereinthe liquid after being cooled in the container is used to cool down anenclosure in a refrigerator.